Endocrine Surgery — MCQs

Endocrine Surgery Indian Medical PG Practice Questions and MCQs

Question 51: A patient with a history of irradiation to the neck presents with a single solitary nodule. What is the most likely diagnosis?

A. Papillary carcinoma of the thyroid (Correct Answer)
B. Follicular carcinoma of the thyroid
C. Medullary carcinoma of the thyroid
D. Hurthle cell carcinoma of the thyroid

Explanation: **Explanation:** The correct answer is **Papillary carcinoma of the thyroid (PTC)**. **Why it is correct:** Exposure to ionizing radiation (especially during childhood or for therapeutic reasons in the neck) is the most significant and well-established environmental risk factor for thyroid cancer. Among all thyroid malignancies, **Papillary Thyroid Carcinoma** is the most common histological type associated with post-radiation exposure. It often presents as a solitary nodule and may have a long latency period (typically 5–20 years) after the radiation event. **Why the other options are incorrect:** * **Follicular carcinoma:** While it is the second most common thyroid cancer, its primary risk factor is iodine deficiency rather than radiation. * **Medullary carcinoma:** This arises from parafollicular C-cells and is strongly associated with genetic mutations (RET proto-oncogene) and MEN 2 syndromes, not radiation. * **Hurthle cell carcinoma:** This is considered a variant of follicular neoplasm and does not show the same strong epidemiological link to radiation as PTC. **Clinical Pearls for NEET-PG:** * **Most common thyroid cancer:** Papillary Carcinoma (85%). * **Characteristic Histology:** Orphan Annie eye nuclei, Psammoma bodies, and Nuclear grooves. * **Route of Spread:** Primarily **Lymphatic** (unlike Follicular, which spreads hematogenously). * **Prognosis:** Generally excellent, though radiation-induced cases may occasionally be multifocal. * **Genetic Association:** Often involves **BRAF mutations** or **RET/PTC rearrangements** (the latter is specifically common in radiation-induced cases).

Question 52: In Werner Syndrome, what is the most common site for Gastrinoma?

A. Pancreas
B. Stomach
C. Colon
D. Small intestine (Correct Answer)

Explanation: **Explanation:** **Werner Syndrome (Multiple Endocrine Neoplasia Type 1 - MEN1)** is characterized by the "3 Ps": Parathyroid hyperplasia, Pituitary adenoma, and Pancreatic/Entero-endocrine tumors. Among the functional pancreatico-duodenal tumors in MEN1, **Gastrinoma** (Zollinger-Ellison Syndrome) is the most common. **Why the Small Intestine is correct:** Historically, gastrinomas were thought to primarily arise in the pancreas. However, it is now well-established that in **MEN1 patients**, the vast majority (up to 85-90%) of gastrinomas are located in the **duodenum (proximal small intestine)**. These are often small, multicentric, and located within the submucosa. This is a high-yield distinction from sporadic gastrinomas, which are more likely to be solitary and can occur in the pancreas. **Analysis of Incorrect Options:** * **A. Pancreas:** While the pancreas is a common site for other MEN1 tumors (like Insulinomas or non-functional tumors), it is *not* the most common site for gastrinomas in Werner Syndrome. * **B. Stomach & C. Colon:** Gastrinomas are extremely rare in these locations. While "G-cells" are found in the stomach antrum, gastrin-secreting tumors (gastrinomas) predominantly arise within the "Gastrinoma Triangle." **NEET-PG High-Yield Pearls:** 1. **Passaro’s Triangle (Gastrinoma Triangle):** Defined by the junction of the cystic/common bile duct, the junction of the 2nd and 3rd portions of the duodenum, and the neck of the pancreas. Most gastrinomas (sporadic and MEN1) are found here. 2. **Most common cause of death in MEN1:** Pancreatico-duodenal tumors (specifically malignant progression). 3. **Screening:** In MEN1, the first biochemical abnormality detected is usually hypercalcemia (due to Hyperparathyroidism). 4. **Surgical Note:** Duodenal gastrinomas in MEN1 are often missed on imaging due to their small size; intraoperative duodenotomy and transillumination are often required.

Question 53: Which of the following are surgical causes of hypercalcemia?

A. Hyperparathyroidism
B. Multiple Endocrine Neoplasia (MEN)
C. Malignancy
D. All of the above (Correct Answer)

Explanation: **Explanation:** Hypercalcemia is a common clinical scenario in surgery, primarily driven by excessive parathyroid hormone (PTH) secretion or bone resorption. The correct answer is **All of the above** because each option represents a distinct surgical etiology of elevated serum calcium. 1. **Hyperparathyroidism:** This is the most common cause of hypercalcemia in the outpatient setting. **Primary Hyperparathyroidism (PHPT)**, usually due to a solitary parathyroid adenoma (85%), results in autonomous PTH secretion, leading to increased bone resorption and renal calcium reabsorption. 2. **Multiple Endocrine Neoplasia (MEN):** Both **MEN 1** (Wermer syndrome) and **MEN 2A** (Sipple syndrome) are characterized by hyperparathyroidism (usually parathyroid hyperplasia). In these genetic syndromes, surgical intervention (subtotal parathyroidectomy) is the definitive treatment. 3. **Malignancy:** This is the most common cause of hypercalcemia in hospitalized patients. It occurs via three mechanisms: * **PTHrP production** (Humoral hypercalcemia of malignancy, common in Squamous Cell Carcinoma of the lung). * **Osteolytic bone metastases** (e.g., Breast cancer). * **1,25-dihydroxyvitamin D production** (e.g., Lymphomas). **Clinical Pearls for NEET-PG:** * **Mnemonic for PHPT:** "Stones, Bones, Abdominal Groans, and Psychic Overtones." * **Most common cause of PHPT:** Solitary Adenoma (85%), followed by Hyperplasia (15%) and Carcinoma (<1%). * **Hungry Bone Syndrome:** A common post-surgical complication after parathyroidectomy characterized by profound hypocalcemia. * **Investigation of Choice:** Sestamibi Scan (Technetium-99m) is used for preoperative localization of adenomas.

Question 54: What is the recommended treatment for anaplastic carcinoma of the thyroid?

A. Total thyroidectomy
B. Palliative radiotherapy (Correct Answer)
C. Radioactive iodine therapy
D. Tracheostomy

Explanation: **Explanation:** Anaplastic Thyroid Carcinoma (ATC) is one of the most aggressive solid tumors in humans, characterized by rapid growth, early local invasion, and distant metastasis. By the time of diagnosis, most patients present with stage IVA/IVB (locally advanced) or IVC (metastatic) disease, making curative surgery impossible. **Why Palliative Radiotherapy is Correct:** The primary goal in ATC is local control to prevent airway obstruction and improve quality of life. Since the tumor is usually unresectable at presentation, **external beam radiotherapy (EBRT)**, often combined with chemotherapy (e.g., Paclitaxel/Doxorubicin), is the standard treatment to shrink the tumor mass and provide palliation. **Analysis of Incorrect Options:** * **Total Thyroidectomy:** This is rarely feasible because the tumor typically invades vital structures (carotid artery, esophagus, trachea) by the time of diagnosis. Surgery is only indicated in the rare event of a small, localized tumor (Stage IVA). * **Radioactive Iodine (RAI) Therapy:** ATC cells are undifferentiated and do not express the sodium-iodide symporter (NIS). Therefore, they do not take up iodine, making RAI completely ineffective. * **Tracheostomy:** While often necessary in emergencies to secure the airway, it is a supportive procedure, not a "treatment" for the cancer itself. It is avoided if possible as it can lead to tumor fungation through the stoma. **NEET-PG High-Yield Pearls:** * **Demographics:** Typically affects elderly patients (6th–7th decade). * **Histology:** Shows spindle, giant, or squamoid cells; p53 mutations are common. * **Prognosis:** Extremely poor; median survival is 3–6 months. * **Diagnosis:** Core needle biopsy or incisional biopsy is often required as FNAC may be inconclusive. * **BRAF V600E:** If present, targeted therapy (Dabrafenib + Trametinib) is now a recommended first-line option.

Question 55: Which investigation is the investigation of choice to differentiate between a benign and malignant thyroid nodule?

A. USG (Ultrasound)
B. FNAC (Fine Needle Aspiration Cytology) (Correct Answer)
C. Scintigraphy
D. Biopsy

Explanation: **Explanation:** The investigation of choice for differentiating between a benign and malignant thyroid nodule is **Fine Needle Aspiration Cytology (FNAC)**. It is the most cost-effective, sensitive, and specific initial test for evaluating thyroid nodules. **Why FNAC is the Correct Answer:** FNAC provides a cytological assessment of the nodule. Based on the **Bethesda System for Reporting Thyroid Cytopathology**, it categorizes nodules into risk groups (Benign, Suspicious, Malignant, etc.), allowing clinicians to decide between observation and surgical intervention. It has a high diagnostic accuracy (approx. 95%). **Why Other Options are Incorrect:** * **USG (Ultrasound):** While USG is the *first* investigation performed to characterize a nodule (looking for features like microcalcifications or irregular margins), it cannot definitively confirm malignancy; it only stratifies risk (TI-RADS). * **Scintigraphy (Radioisotope Scan):** This assesses the *functional* status of a nodule. While "cold" nodules have a higher risk of malignancy (15-20%) than "hot" nodules, it cannot provide a tissue diagnosis. * **Biopsy (Core/Incisional):** Routine core needle biopsy is generally avoided in thyroid nodules due to the risk of bleeding and potential seeding. FNAC is preferred as it is less invasive. **High-Yield Clinical Pearls for NEET-PG:** * **Limitation of FNAC:** FNAC **cannot** differentiate between **Follicular Adenoma and Follicular Carcinoma** because it cannot assess capsular or vascular invasion. Histopathology (post-surgery) is required. * **Best Initial Test:** USG. * **Most Accurate/Investigation of Choice:** FNAC. * **Gold Standard:** Histopathology (Biopsy) after thyroidectomy.

Question 56: Which of the following thyroid carcinomas has the worst prognosis?

A. Follicular carcinoma
B. Papillary carcinoma
C. Anaplastic carcinoma (Correct Answer)
D. Medullary carcinoma

Explanation: **Explanation:** The prognosis of thyroid carcinomas is primarily determined by the degree of cellular differentiation. **Anaplastic carcinoma (Option C)** is an undifferentiated tumor and is considered one of the most aggressive solid tumors in humans. It typically presents in elderly patients as a rapidly enlarging neck mass with early local invasion and distant metastasis. The 5-year survival rate is dismal (often <5%), making it the thyroid malignancy with the worst prognosis. **Analysis of Incorrect Options:** * **Papillary Carcinoma (Option B):** This is the most common thyroid cancer and has the **best prognosis**. It spreads primarily via lymphatics but is highly treatable with an excellent 10-year survival rate (>90%). * **Follicular Carcinoma (Option A):** This is the second most common type. While it carries a slightly worse prognosis than papillary carcinoma due to early hematogenous spread (to bone and lungs), it is still considered a well-differentiated cancer with a favorable outcome. * **Medullary Carcinoma (Option D):** Arising from parafollicular C-cells, its prognosis is intermediate—worse than differentiated cancers (Papillary/Follicular) but significantly better than Anaplastic carcinoma. **High-Yield Clinical Pearls for NEET-PG:** * **Most Common:** Papillary Carcinoma (associated with *RET/PTC* rearrangements and *BRAF* mutations). * **Psammoma Bodies:** Characteristic histological finding in Papillary Carcinoma. * **Orphan Annie Eye Nuclei:** Pathognomonic for Papillary Carcinoma. * **Medullary Carcinoma:** Associated with MEN 2A/2B syndromes; secretes **Calcitonin** (used for diagnosis and follow-up). * **Hurthle Cell Carcinoma:** A variant of Follicular carcinoma; does not take up iodine well. * **Anaplastic Carcinoma:** Often associated with *p53* mutations and may arise from pre-existing differentiated thyroid cancer.

Question 57: An infant is diagnosed with MEN-2B syndrome. Which of the following is the best line of management?

A. Prophylactic thyroidectomy (Correct Answer)
B. Clinical observation and follow-up
C. Regular fine-needle aspiration cytology (FNAC)
D. Management depends on the specific manifestations

Explanation: **Explanation:** **1. Why Option A is Correct:** Multiple Endocrine Neoplasia Type 2B (MEN-2B) is characterized by a 100% penetrance of **Medullary Thyroid Carcinoma (MTC)**. In MEN-2B, MTC is exceptionally aggressive, presenting earlier and metastasizing faster than in MEN-2A. Current clinical guidelines (American Thyroid Association) mandate **prophylactic total thyroidectomy** as soon as the diagnosis is made, ideally **within the first year of life** (often before 6 months), because MTC can develop and spread in infancy. **2. Why Other Options are Incorrect:** * **Option B & C:** Clinical observation or regular FNAC are dangerous strategies. By the time a nodule is palpable or detectable via FNAC, the carcinoma has often already metastasized to regional lymph nodes, significantly worsening the prognosis. * **Option D:** While MEN-2B involves other manifestations (marfanoid habitus, mucosal neuromas, pheochromocytoma), the management of the thyroid is **not** expectant. The risk of MTC is so high and predictable that immediate surgical intervention is the standard of care regardless of other symptoms. **3. High-Yield Clinical Pearls for NEET-PG:** * **Genetics:** MEN-2B is associated with the **RET proto-oncogene** mutation (specifically codon M918T). * **Components of MEN-2B:** MTC, Pheochromocytoma, Mucosal neuromas (tongue/lips), Marfanoid habitus, and Ganglioneuromatosis of the GI tract. * **Timing of Surgery:** * **MEN-2B:** Prophylactic thyroidectomy in **infancy (<1 year)**. * **MEN-2A:** Prophylactic thyroidectomy usually by **age 5**. * **Tumor Marker:** Serum **Calcitonin** levels are used for screening and monitoring recurrence of MTC. Always rule out Pheochromocytoma before performing thyroid surgery to prevent a hypertensive crisis.

Question 58: Which statement is false regarding adrenal adenoma?

A. Usually less than 4 cm in size.
B. Should be excised if symptomatic or large.
C. Presents as an abdominal mass. (Correct Answer)
D. Can cause Cushing's syndrome.

Explanation: ### Explanation **1. Why "Presents as an abdominal mass" is the False Statement:** Adrenal adenomas are typically small, benign tumors. Due to their deep retroperitoneal location and small size (usually <4 cm), they are **almost never palpable** as an abdominal mass. A palpable adrenal mass is a "red flag" that strongly suggests **Adrenocortical Carcinoma (ACC)**, which is usually >6 cm at the time of presentation, or a large neuroblastoma in children. **2. Analysis of Other Options:** * **A. Usually less than 4 cm in size:** This is true. Most adenomas are small. The "4 cm rule" is a clinical threshold; lesions >4 cm have a higher risk of malignancy and are generally recommended for surgical resection. * **B. Should be excised if symptomatic or large:** This is true. Indications for adrenalectomy include functional (hormone-secreting) tumors regardless of size, or non-functional tumors that are large (>4 cm) or showing rapid growth, due to the risk of malignancy. * **D. Can cause Cushing's syndrome:** This is true. Adrenal adenomas can be "functional." An ACTH-independent Cushing’s syndrome is frequently caused by a cortisol-secreting adrenal adenoma. **3. NEET-PG High-Yield Pearls:** * **Incidentaloma:** An adrenal mass found unexpectedly on imaging for unrelated reasons. Most are non-functional adenomas. * **Imaging Gold Standard:** Non-contrast CT. Adenomas typically have **low Hounsfield Units (HU <10)** due to high intracellular lipid content. * **Washout Profile:** Adenomas show rapid contrast washout (>60% absolute washout at 15 minutes). * **Rule of 10s:** While traditionally associated with Pheochromocytoma, remember that for any adrenal mass, you must biochemically rule out Pheochromocytoma before biopsy or surgery to avoid a hypertensive crisis.

Question 59: All of the following are true about hyperparathyroidism except?

A. Solitary adenoma
B. Malignant
C. Thyroid malignancy (Correct Answer)
D. Parathyroid hyperplasia

Explanation: This question focuses on the common causes and associations of **Primary Hyperparathyroidism (PHPT)**. ### **Explanation** Primary hyperparathyroidism is characterized by the autonomous overproduction of parathyroid hormone (PTH), leading to hypercalcemia. * **Why Option C is the Correct Answer:** **Thyroid malignancy** is not a cause of hyperparathyroidism. While thyroid nodules may coexist with parathyroid adenomas, a malignancy of the thyroid gland itself does not result in the hypersecretion of PTH. (Note: Medullary Thyroid Carcinoma is associated with PHPT in MEN 2A syndrome, but the PHPT is caused by parathyroid hyperplasia, not the thyroid cancer itself). ### **Analysis of Incorrect Options** * **Option A (Solitary Adenoma):** This is the **most common cause** of PHPT, accounting for approximately **85-90%** of cases. It usually involves a single gland. * **Option B (Malignant):** Parathyroid carcinoma is a rare but recognized cause of PHPT (<1%). It is characterized by very high calcium levels (>14 mg/dL) and a palpable neck mass. * **Option D (Parathyroid Hyperplasia):** This involves all four glands and accounts for about **10-15%** of cases. It is frequently associated with familial syndromes like **MEN 1 and MEN 2A**. ### **Clinical Pearls for NEET-PG** * **Most common symptom:** Most patients are asymptomatic today ("Asymptomatic hypercalcemia"). Classic symptoms are "Bones, Stones, Abdominal Groans, and Psychic Moans." * **MEN 1 (Wermer’s Syndrome):** Parathyroid hyperplasia is the most common and earliest manifestation. * **Sestamibi Scan (Technetium-99m):** The investigation of choice for localizing a parathyroid adenoma before surgery. * **Hungry Bone Syndrome:** A common postoperative complication following parathyroidectomy, leading to profound hypocalcemia.

Question 60: A patient presents with a sudden increase in the size of a thyroid swelling accompanied by pain. What is the most likely cause?

A. Hemorrhage within the cyst (Correct Answer)
B. Malignant change
C. Nodular goiter
D. Colloid goiter

Explanation: ### Explanation **Correct Option: A. Hemorrhage within the cyst** The clinical triad of **sudden increase in size**, **pain**, and **tenderness** in a pre-existing thyroid nodule is a classic presentation of **hemorrhage into a thyroid cyst** or a degenerate nodule. This occurs because the rapid expansion of the cyst stretches the thyroid capsule, which is richly innervated with sensory nerves, leading to acute localized pain. **Analysis of Incorrect Options:** * **B. Malignant change:** While thyroid cancers (especially Anaplastic carcinoma) can grow rapidly, they are typically painless and present as a hard, fixed mass. Pain is a late feature associated with local invasion, not a sudden onset symptom. * **C. Nodular goiter:** This refers to a multinodular goiter (MNG), which usually progresses slowly over years. It is generally painless unless a specific complication like hemorrhage or secondary malignancy occurs. * **D. Colloid goiter:** This is a benign, diffuse enlargement of the thyroid due to accumulation of colloid. It is a chronic, painless condition and does not present with sudden acute changes. **Clinical Pearls for NEET-PG:** * **Management:** The initial management for a painful, hemorrhagic cyst is **Fine Needle Aspiration (FNA)**. This is both diagnostic and therapeutic, as it relieves the pressure and pain immediately. * **Anaplastic Carcinoma:** If a patient presents with a rapid increase in size *without* pain but with symptoms like hoarseness or dysphagia, suspect Anaplastic Carcinoma. * **De Quervain’s Thyroiditis:** Another cause of painful thyroid is Subacute Granulomatous Thyroiditis, but this is usually associated with systemic symptoms (fever, malaise) and elevated ESR, rather than a localized "swelling" that suddenly enlarges.

Practice by Chapter

Thyroid Nodules

Practice Questions

Thyroid Cancer

Practice Questions

Graves' Disease

Practice Questions

Thyroiditis

Practice Questions

Primary Hyperparathyroidism

Practice Questions

Secondary and Tertiary Hyperparathyroidism

Practice Questions

Adrenal Cortical Tumors

Practice Questions

Pheochromocytoma

Practice Questions

Adrenal Incidentalomas

Practice Questions

Multiple Endocrine Neoplasia

Practice Questions

Neuroendocrine Tumors

Practice Questions

Intraoperative Monitoring in Endocrine Surgery

Practice Questions

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